Valve tappet



C. VOORHIES Aug. 18, 1936.

VALVE TAPPET Filed April 25, 1950 INVENTOR. gab/M ATTO EY Patented Aug.18, 1936 4 UNITED STATES VALVE 'rarrn'r I Carl Voorhies, Buffalo. N..Y., assignor, by assignments, to Wilcox Rich Corporation, Detroit,Mich., a corporation oi Michigan Application April as, 1930, ,Serial No.447,243

' 8 Claims. (01. 123-90) This invention relates to internal combustionengines and particularly tothe poppet valves which are operated by valvetappets riding on cams on a cam shaft.

Heretofore it has been customary to provide va poppet valve which isseparated from the end of v the valve stem by a clearance to permit anexfrom seating, especially when the valvestem has become expanded due tothe heat from themglue and oftentimes the valves are burned out due tothe close adjustment.

Therefore my present invention has for its object to provide a valveoperating mechanism which will eliminate the clearance in question andwith it any noise produced by the valve tappet striking the valve.

A further object is to provide a column of liquid under pressure betweenthe valve tappet and a plunger slidably supported therein to alwaysmaintain the latter in contact with the valve stem, with the result thatthe noises are eliminated and the quietness of the engine is improved.

The above being among the objects of the present invention, the sameconsists of certain features of construction and combination of parts tobe hereinafter described with reference to the accompanying drawing, andthen claimed, having the above and other objects in view.

In the accompanying drawing which illustrates a suitable embodiment ofthe present invention,

Figure 1 is a fragmentary sectional view of an internal combustionengine, showing the valve in raised position and my invention associatedtherewith.

Figure 2 is a transverse sectional view taken on the line 2-2 of Figure1.

Figure 3 is a view similar to Figure 1, showing a modified form ofinvention.

Figure 4'is an enlarged detail view showing the oil seal between thevalve tappet and plunger supported therein.

In the drawing in which like numerals refer to like parts throughout theseveral views, l indicates the engine casing provided with the usualpoppet valve ll having a stem i2 extending downwardly therefrom passingthrough the valve stem guide I3. The valve stem l2 has'the usual springsupport l4 thereon-adjacent to its lower end supporting the customaryvalve spring ll 5 positioned between the support l4 and a portion of theengine It to 'urge thevalve ll toward its seated position. The cam shaft16 has a cam I] thereon engaging with a push rod base It secured in'thepush rod i9 slidable in the guide 20 1 secured in the usual manner inthe engine Hi. The push rod is is bored out at 2i to receive the plunger22 having a hardened head 23 mounted therein adapted to always engagewith the end of. the valve stem l2. A bushing 24 is seated in the bottomof the bore 2| on which is positioned a spring '25 seating against ashoulder 28 on the plunger 22 to constantly urge the hardened head 23 inthe plunger 22 against theend'of the valve stem i2. The bushing 24 ispreferably cupshaped, the end wall thereof being provided with openings21 therein to provide a cag'e'for the check valve 28 normally seating onthe'pushrod I! to close the port 29 therein for 9' pose to behereinafter'described. The inner surface of the 26 end wall of bushing24 serves to limit movement of the check valve 28 away from its valveseat to a slight distance. The lower end of the plunger 22 is spacedfrom the bushing 24 to provide clearance therebetween and ismaintainedin that positi n by liquid, which is preferably oil, forcedinto hechamber through the pipe 30 from the engine oil pump, not'shown.However, in the event that the liquid fails to sustain "theplunger insuch spaced relation,-due to such causes as failure of the liquid supplyor leakage of liquid by thecheck valve 28, the outer surface of the endwall of bushing 24 serves as a stop for limitinginward movement of theplunger, 22 into the. bore 2i of push rod IS, the bushing 24 alsoserving at all times to prevent'both the plunger 22 and check valve 28from-"interfering with the action of each other. Thesuide 20 for thepush rod I9 is preferably bored out to provide a chamber 2| extendingaround a portion of the push rod l9 as is clearly shown in Figure 1, thec'hamberiil communicating with the pipe and the passageway 29 to permiton to be pumped from'the pipe 30 to the chamber within thepush rod ll.

During the operation of the engine, the cam H on the cam shaft l6willraisethe push rod base it as is shown in Figure 1, thus moving thepush rod l9 upwardly and forcing the valve ll to open position againstthe compression of the spring l5. As the cam l'l rotates, the valve llwill move toward its seated position due to the expansion of the springI I and the valve stem -|2 will follow downwardly in contact with thehead 23 in the plunger 22. The oil pressure in,

the chamber in the push rod It will always force the plunger 22 intocontact with the valve sternv l2 and oil pressure will be maintained inthe chamber by the check valve 2|.

I preferably position the pipe 30 above the.

check valve 28 so that any leakage of oil out of the chamber in the pushrod I 8 will flow into the chamber 3i and be trapped therein and will""not flow back into the pump through the pipe ll.

This construction has anadvantage because of the fact that when theengine has been at rest for sometime, there is a tendency for the oil toleak out of the chamber in the push rod I! so ring 32 around the lowerportion of the plunger 22 against which is seated a metal cup-shapedwasher 32 to form an oil seal, these members being held in operativeposition by means of the spring 2!. I In Figure 3 I have shown the.construction heretofore described to which the same numerals have beenapplied, excepting that the guide 20 for the push rod II is providedwith an oil receptacle 35 whereby the oil is permitted to flow bygravity into the chamber in the push rod ll to maintain the pressuretherein in the same manner as previously described.

It is necessary to prevent to the greatest possible degree air or gasesfrom entering the hydraulic ccmpressionchamber 2i in the tappet body forthe reason that the inclusion of air therei renders the hydraulic mediumcompressible in this chamber, therebymaking it impossible to control, asprecisely as necessary, the

amount the poppet valve I I is raised from its seat.

a So long as the hydraulic medium admitted to or contained in thecompression chamber 2| is in-' compressible, the timing and degree ofopening the valves can be closely controlled, This-is essential toefllcient operation. The construction and placement of the oil reservoirii and the relative position of the valve control passage 2! leadingfrom the compression chamber in-the tappet to the, oil reservoir II andthe position of I the oil inlet 30 are therefore very important factorsin the control of air and gases included in the oil delivered throughthe oil line 30 and the prevention of the entry of such air or gasesinto the compression chamber 2i in the tappet body;

The oil reservoir 3| comprises an annular recess formed in the tappetguide 2| which is stationary. The peripheral surface of the tappet bodyI! is smooth and unrelieved and slides past this oil reservoir 2 Iwithout disturbing or chuming the oil contained in the reservoir,thereby permitting air or gases carried in through the oil line 30 tocollect at the top of the-annular recess SI and remain there until theyare worked out upwardly between the exterior surface of the tappet bodyand the guide. The passage 20 in the tappet body leading from the oilreservoir 31 in the tappet guide to the compression chamber 2| in thetappet body is so positioned and placed that during the entirereciprocation of the tappet it remains substantially below the-upperlimits,

of the annular recess or, oil reservoir 3| in. the tappet guide, andtherefore never comes into communication with the air or gases collectedin the upper portion of the oil reservoir Ii, consequently preventingthe induction of such air or gases into the compression chamber in thetappet body. The compression chamber 2| in the tappet body is sealed bythe washer a at the upper end and the only communication it may havewith the outside of the tappet isthrough the valve control passage 2!which ismaintained out of the region of the collected air and gases inthe upper part of the oil reservoir it during the entire reciprocationof the tappet.

The use of tappets constructed in accordance with the present inventionserves to eliminate the valve noises and the loss of emcienc'y caused 20by wear and excessive lost motion and still the tappet. contains itscompensating mechanism within itself to operate in an effective manner.'While I have described certain embodiments of my invention in detail itis to be understood 25 upper end thereof, a spring mounted plunger and35 sealing means therefor in said chamber'ya single valve controlledpassage leading from said chamber to'the outside of said tappet body, acylindrical guide for said tappet having an annular recess thereinforming a stationary oil reservoinand an oil passage leading outwardlyfrom the upper portion of said recess, said tappet body and valvecontrolled passage leading into the hydraulic.

' line of communication with said tappet hydraulic r. 2. In a hydraulictappet organization, the combination of a stationary oil reservoir inthe tappet guide comprising an elongated annular recess in the innersurface thereof, an-unrelieved tappet body reciprocable in said guidewithout churning ,the'oil in said reservoir, a sealed compressionchamber in said tappet body and a valve controlled passage in saidtappet body communi eating said compression chamber only with the lowerportion of said oil reservoir, whereby the oil in said reservoir isrelatively undisturbed during reciprocation of said tappet body and freefrom included air in the region ,of communica body, a valve controlledpassage leading from said compression chamber to the outside of saidtappet body and communicating with said gas separation chamber at pointsbelow the upper end of the latter during the entire reciprocatorymovement of said tappet body, whereby the upper portion of said gasseparation chamber serves as a gas trap at all times out ofcommunication with said valve controlled passage, and means for ventinggas from the upper end of said gas separation chamber.

4. In a hydraulic tappet organization, the combination of a tappetguide, a tappet body reciprocable in said guide, an oil settlingand gassepation chamber arranged exteriorly oi! said tappet body, a compressionchamber in said tappet body, a spring mounted plunger in saidcompression chamber for drawing oil into the latter, a valve controlledpassage leading from said compression chamber to the outside of saidtappet body and communicating during reciprocation of said tappet bodywith the lower portion 01' said gas separation chamber but out ofcommunication at all times with the upper portion of the gas separationchamber, whereby the upper portion of said gas separation chamber servesas a gas trap at all times out of line communication with said valvecontrolled passage, the upper end of said gas separation chamber beingvented to atmosphere through the clearance between said tappet body andsaid tappet guide. v

5. In a reciprocating self-adjusting hydraulic valve operating device ofthe 'class described, the combination of a valve seat, a free non-returnvalve for opening and closing said seat under the action of gravity andits own inertia, a plunger reciprocable in said device, and means forlimiting the travel of said free valve away from its seat and forlimiting inward'movement of said plunger into said device.

6. In a reciprocating hydraulic tappet of the class described, a hollowcylinder, 9. non-return valve controlled fluid port in the'bottom ofsaid 5 cylinder, a ball valve for said port and free to open and closethe latter under the action of gravity and its own inertia, and anapertured cage member for limiting the movement of said nonreturn valverelative to said port and'for guarding the non-return valve againstinterference with said plunger.

7. In a reciprocating hydraulic tappet of the class described, theconstruction comprising the combination of a cylinder having a fluidport at one end thereof, a plunger reciprocable in said cylinder, avalve in the bottom of said cylinder free to open and close said portunder the action of gravity and its own inertia, a valve seat for saidvalve, and an apertured cage member secured in said cylinder forlimiting movement of said valve away from its seat and for guarding saidvalve from interference with said plunger.

8. In a reciprocating hydraulic tappet of the class described, theconstruction comprising the 25,

combination of a cylinder having a fluid port at one end thereof, aplunger reciprocable in said cylinder, a ball valve in the bottom ofsaid cylinder free to open and close saidport under the action ofgravity and its own inertia, a valve seat for said ball valve, and aninverted cup-shaped and apertured cage member secured in said cylinderfor limiting movement of said ball valve away from its seat and forguarding said ball' valve from interference with said plunger.

CARL vooanms.

